1. Field of the Invention
The present invention relates to a method and an apparatus for packaging. More particularly, the present invention relates to a method and an apparatus for packaging a substance by using packaging material such as packaging film, packaging sheets or packaging containers to which a freshness-keeping member is automatically attached to form a package for foodstuffs for example. To be more specific, the present invention relates to securing a freshness-keeping agent to be enclosed within a package for foodstuffs such as confections, coffee, soy bean flour, grain, beans, rice, rice cake, noodles, such as Chinese noodles, ham, salami, sausage and delicacies, and also relates to a method and an apparatus for automatically attaching a freshness-keeping member on the inside of the packaging film or on the cover of a container that forms a package for foodstuffs and the like.
2. Description of the Related Art
Freshness-keeping agents, such as oxygen absorbers or desiccating agents for example, have been placed in a small bag made of gas permeable packaging material (hereinafter referred to as the "freshness-keeping-agent bag"). Conventionally, most of such freshness-keeping-agent bags have been placed within the final package product without being secured thereto.
However, without securing the freshness-keeping-agent bag to the package, it is likely that the consumer will. accidentally eat, or cook the freshness-keeping agent with the foodstuff when the consumer opens the package. The freshness-keeping-agent bags then began to be secured to the package. Although various methods for securing the freshness-keeping-agent bags have been applied, there are problems with each of such methods.
For example, a method for securing the freshness-keeping-agent bag by compressing a sealed portion of the freshness-keeping-agent bag to a sealed portion of the package has been adopted. In this method, however, the surface of the sealed portion of the package is uneven, and thus uniform compression cannot be achieved at the time of sealing. Therefore, air-tightness may not be maintained because the sealing strength is rather weak. In recent years, a method for securing the freshness-keeping-agent bag to the packaging film by using double-coated tape has been developed. This method has durability problems when it is cooked in a micro wave oven and the like because the freshness-keeping-agent bag may fall off the packaging member.
In order to solve the problems concerning heat resistance or bonding strength, and because of the necessity to automate the production of the package, a method to automate the process of securing the freshness-keeping-agent bag to the packaging film by using hot-melt adhesive was proposed in patent application laid-open publication No. Hei 3-56224.
A method for securing the freshness-keeping-agent bag was disclosed in that publication wherein a hot-melt adhesive is dropped on a predetermined position on the inner surface of the packaging film and the freshness-keeping-agent bag is secured to the packaging film on which the hot-melt adhesive is attached.
However, in this method for securing the freshness-keeping-agent bag, if the manufacturer intends to increase production capacity by installing, in a longitudinal or lateral direction, a plurality of packaging machines for automatically producing, by using packaging film, the final package product, an apparatus for dropping the hot-melt adhesive would be necessary for each position of the wrapping film on which the freshness-keeping-agent bag is secured. As a result, not only is an increase of peripheral machines necessary, but a large space for installing such facilities is also required. Improvements have therefore not been obtained.
Moreover, if the processing capability of the packaging machine itself is improved, the speed of supplying packaging material such as packaging film will increase. However, it is difficult to synchronize and match the position on the packaging film for dropping hot-melt adhesive with the freshness-keeping-agent bag.
Among the prior art described above, no significant disadvantage would arise for packaging machines which have a function that would stop the cycle of supplying the packaging material, such as a deep drawing automatic vacuum packaging machine or cup sealer. Recently, there has been a need to attach the freshness-keeping-agent bags without stopping the cycle of the packaging machines. In such packaging machines, it has been extremely difficult to drop the hot-melt adhesive to the predetermined position on the packaging material, and to secure the freshness-keeping-agent bag to the predetermined position.
Furthermore, when the operation of throwing the freshness-keeping-agent bags into the package is performed at places such as a food packaging room where the humidity is high, the sliding capability of the chute that is used to slide the freshness-keeping-agent bags is not favorable, and thus, it has been difficult to steadily supply the freshness-keeping-agent bags at a fixed distance.
It is difficult to change the size of the freshness-keeping-agent bags to match various types of foods because it is burdensome to change the size of the chute in order to match the size of such bags.
In more and more cases of other embodiments of the prior art, a freshness-keeping agent is being used along with a detection agent (such as oxygen detection agent) for detecting the conditions within the package by observing the change of the color of the detection agent, which enables the preservation of the foodstuff by checking whether or not the air-tightness within the non-porous package which contains the foodstuff is being maintained.
Through the use of the detection agent together with the freshness-keeping agent, small holes produced on the surface of a non-porous bag, deficiencies in the seal, or a rise in the oxygen concentration or humidity within the sealed system due to the deterioration of the freshness-keeping capability of the freshness-keeping agent can be determined.
However, conventionally, since the freshness-keeping-agent bag and the detection agent had been separately packaged, if the freshness-keeping agent and the detection agent were enclosed together within the package of foodstuff, the operational efficiency was poor because it required much labor. Moreover, it is difficult to find the detection agent even though it is placed within the package of food because it is small, and moreover, it takes time to recognize the conditions within the package. Because the freshness-keeping agent and detection agent are not secured to the package, the problem still remains that the consumer may eat or cook the freshness-keeping agent or detection agent with the food after opening the package.
In order to solve these problems, the object of the present invention is to provide a method and an apparatus for packaging a substance, wherein, when the freshness-keeping-agent bag is secured to a belt-like member, such as a belt-like member of the packaging material or a belt-like member of the detection agent, there is no or very little variation in the secured position and wherein the synchronization and matching of the freshness-keeping-agent bag with a belt-like member is rather easy.
Another object of the present invention is to provide a method and an apparatus for packaging a substance by using the packaging film to which a freshness-keeping-agent bag is attached, wherein, if the production capacity of the packaging machine for automatically producing the final package product is improved, or if production capacity is increased by installing a plurality of such packaging machines, problems with regard to an increased number of facilities or space will not arise, moreover, no obstacles will arise in securing the freshness-keeping-agent bags to the packaging film.
Another object of the present invention is to provide an apparatus for packaging that is capable of constantly supplying the freshness-keeping-agent bags in an uniform distance, wherein the sliding capacity of the chute is favorable.
Another object of the present invention is to provide an apparatus for packaging for which it is not necessary to change the chute even if the size of the freshness-keeping-agent bag varies.
Another object of the present invention is to provide a method and an apparatus for packaging by which the operation of enclosing the freshness-keeping-agent bag and the detection agent within the package is simplified, the detection agent within the package can be quickly recognized and which prevents accidents such as the consumer eating the freshness-keeping agent or detection agent upon opening the package.